Problems may be encountered during fabrication of semiconductor constructions when large mesas of semiconductor material are spaced from one another by regions of intervening material, as described with reference to FIGS. 1 and 2.
FIG. 1 shows a semiconductor construction 10 comprising a semiconductor material 12 patterned into a pair of mesas 14 and 16. The semiconductor material may comprise, for example, silicon. The mesas 14 and 16 are spaced from one another by an intervening region 20.
Intervening material 18 is adjacent the mesas and between the mesas. Such intervening material may comprise, for example, silicon dioxide. The intervening material 18 fills the intervening region 20.
The mesas 14 and 16 have widths along the cross-section of FIG. 1 of “A” and the intervening region 20 has a width along such cross-section of “B”. The dimension “A” is much larger than the dimension “B”. In some applications, “A” may be at least about 400 nanometers (nm), and “B” may be less than or equal to about 250 nm.
The intervening material 18 has stresses associated therewith, and such stresses can induce defects within the semiconductor material of mesas 14 and 16. For instance, FIG. 2 shows construction 10 after thermal processing and diagrammatically illustrates propagation of dislocations (indicated by dashed lines 19) within the semiconductor material 12 of mesas 14 and 16. Such dislocations may occur, for example, during crystallization of semiconductor material 12 in a thermal anneal.
In some applications integrated circuitry extends into the semiconductor material of mesas 14 and 16. The defects induced within the mesas may reduce reliability of such circuitry, or may even render the circuitry inoperable. Accordingly, it is desired to develop architectures which alleviate defect formation within the semiconductor material of mesas 14 and 16.